Lightning Strike in Florida, June 21, 2007

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
1018 AM EDT THU JUN 21 2007

.UPDATE...LATEST SURFACE OBSERVATIONS AND VISIBLE SATELLITE
IMAGERY INDICATE THE PRESENCE OF SEVERAL MESOSCALE CONVERGENCE
BANDS ACROSS SOUTH FLORIDA WITHIN THE GENERAL WEAK SW LOW-LEVEL
FLOW. ONE SUCH BAND WAS LOCATED ACROSS MIAMI-DADE AND SOUTHERN
MAINLAND MONROE COUNTIES...WITH ANOTHER LOCATED FROM NEAR WEST
PALM BEACH TO EVERGLADES CITY...AND A THIRD FORMING ACROSS HENDRY
COUNTY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEEN
DEVELOPING ALONG THESE BOUNDARIES ALREADY THIS MORNING...AND WITH
DAYTIME HEATING AND MODERATE INSTABILITY THIS TREND SHOULD
CONTINUE ESPECIALLY AS MID LEVEL SHORTWAVE SEEN ON WATER VAPOR
IMAGERY CONTINUES TO PUSH THROUGH THE REGION. MAIN SURFACE TROUGH
ASSOCIATED WITH SURFACE LOW JUST SOUTH OF JACKSONVILLE STILL LIES
ACROSS CENTRAL FLORIDA...AND MAY CLIP LAKE OKEECHOBEE/PALM BEACH
AND GLADES COUNTY AREA WITH MORE SCATTERED CONVECTION EARLY THIS
AFTERNOON. MAIN CHANGE TO THE GOING FORECAST PACKAGE WAS TO EXTEND
CHANCE POPS SOUTH ALL THE WAY INTO MIAMI-DADE COUNTY GIVEN CURRENT
RADAR/SATELLITE TRENDS. A GRADUAL INCREASE IN COVERAGE COULD BE
EXPECTED THIS AFTERNOON AS THESE BOUNDARIES MOVE E/SE ACROSS THE
AREA AND CONVERGENCE INCREASES AS A WEAK EAST COAST SEA BREEZE
DEVELOPS ACROSS THE EAST COAST METRO AREAS.

.AVIATION...CURRENT/12Z TAFS ARE CARRYING VICINITY THUNDER THIS
AFTERNOON...AND GIVEN CURRENT TRENDS ITS REASONABLE TO BELIEVE
SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE EAST COAST
TERMINALS AFTER 16Z. THINK THAT WITH THE SW FLOW MOST ACTIVITY
WILL REMAIN EAST OF KAPF. WEAK SW FLOW WILL CONTINUE THROUGH MID
DAY BUT THEN A SEA BREEZE SHOULD FORM ALONG THE EAST COAST AND
PUSH INLAND...BRINGING A WIND SHIFT TO THE S OR SSE AT MOST OF THE
EASTERN TERMINALS.

STRASSBERG

&&

.PREV DISCUSSION... /ISSUED 351 AM EDT THU JUN 21 2007/

SYNOPSIS...HIGH PRESSURE CONTINUES TO PARKED OVER THE WESTERN
ATLANTIC WHILE A SURFACE LOW AND ASSOCIATED TROUGH CONTINUE TO MEANDER
OVER NORTHERN AND CENTRAL FLORIDA.

DISCUSSION...SLASHED POPS ACROSS THE SOUTHERN HALF ONCE AGAIN
THIS MORNING AS IT APPEARS THAT MOISTURE IS NOT MOVING IN THAT FAST
AND THE TROUGH WILL LIKELY NOT PUSH THAT FAR SOUTH. OVER THE PAST
COUPLE OF DAYS THE GUIDANCE WAS SUGGESTING THAT THE TROUGH OVER
NORTHERN FLORIDA WOULD PUSH INTO SOUTH FLORIDA, BUT THIS NOW
APPEARS THAT THIS WILL NOT BE THE CASE. THE ONLY LIFT ACROSS THE
AREA WILL BE DUE TO SEA BREEZES AND POSSIBLY OUTFLOW BOUNDARIES
OVER THE LAKE REGION, AND THE SEA BREEZES MAY NOT BE ENOUGH TO ALLOW
FOR MUCH CONVECTION ALONG THE WEST COAST OR ACROSS MIAMI-DADE OR
BROWARD COUNTIES WITH THE AMOUNT OF DRY AND WARM AIR IN THE MID TO
LOW LEVELS. REDUCED POPS TO 20% ALONG COASTAL SECTIONS EXCEPT FOR
IN PALM BEACH, BUT THIS TOO MAY BE GENEROUS LIKE YESTERDAY. ACROSS
INTERIOR SOUTH FLORIDA AND AROUND THE LAKE REGION WITH THE WEST
COAST SEA BREEZE PUSHING WELL INLAND WITH THE SOUTHWEST FLOW AND
WITH AMPLE AFTERNOON HEATING SCATTERED SHOWERS AND THUNDERSTORMS
MAY OCCUR. BASICALLY IT LOOKS LIKE TODAY MAY BE A REPEAT OF
WEDNESDAY, BUT WITH SLIGHTLY MORE CONVECTION POSSIBLE ALONG THE
EAST COAST SEA BREEZE. FRIDAY NOW APPEARS THAT HIGH PRESSURE WILL
REMAIN IN CONTROL ONCE AGAIN AND POPS HAVE ALSO BEEN REDUCED. A
TROPICAL WAVE IS STILL EXPECTED TO MOVE ACROSS SOUTH FLORIDA ON
SATURDAY MORNING. THIS MAY CAUSE SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF THE AREA AS PWATS INCREASE TO AROUND
2, BUT THIS TOO CONTAINS SOME UNCERTAINTY. THERE IS A CHANCE THAT
MOST OF THE MOISTURE MAY PASS SOUTH OF THE REGION AND THIS WOULD
LEAD TO SLASHING POPS ONCE AGAIN. AT THE MOMENT WENT WITH THE GFS
SOLUTION WHICH KEEPS THE MOISTURE OVER SOUTH FLORIDA UNLIKE THE
DRIER NAM. AFTER SATURDAY THE SUBTROPICAL RIDGE IS EXPECTED TO BEGIN
TO BUILD NORTH OF SOUTH FLORIDA AND INCREASE THE PRESSURE GRADIENT
ACROSS OUR REGION. THIS WILL LEAD TO AN INCREASE IN THE EASTERLY FLOW
ACROSS THE AREA AND IN TURN PUSH THE EAST COAST SEA BREEZE WILL
INLAND EACH DAY DECREASING POPS ALONG THE ATLANTIC COAST. THIS MAY
ALSO CREATE MORE CONVECTION ALONG THE WEST COAST SEA BREEZE AND
INTERIOR.

AVIATION...LIGHT SW WINDS WILL BECOME SE AT THE EAST COAST TERMINALS DURING THE
AFTERNOON AS THE SEA BREEZES DEVELOPS AND PUSHES INLAND. WX
CONDITIONS WILL BE MUCH LIKE YESTERDAY WITH CONVECTION EXPECTED TO
REMAIN MOSTLY INLAND...BUT COULD APPROACH PBI SO WILL LEAVE VCTS IN
THERE. OTHERWISE...PREVAILING VFR CONDITIONS ARE EXPECTED.

MARINE...OUTSIDE OF THUNDERSTORM INFLUENCES LIGHT WINDS ARE
EXPECTED ACROSS THE AREA THROUGH THE WEEKEND AND THIS SHOULD KEEP
WAVES AT 3 FEET OR LESS. AFTER SATURDAY THE SUBTROPICAL RIDGE IS
EXPECTED TO BUILD NORTH OF THE REGION AND INCREASE THE PRESSURE
GRADIENT WHICH WILL IN TURN INCREASE WIND SPEEDS TO POSSIBLY
AROUND 15 KNOTS BY EARLY NEXT WEEK.

FIRE WEATHER...NO CONCERNS AT THIS TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  89  75  89  75 / 30 30 30 20
FORT LAUDERDALE  88  77  90  76 / 30 20 20 20
MIAMI            89  75  90  74 / 30 10 20 20
NAPLES           91  74  90  75 / 30 10 20 20

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

LONG TERM...04/AT
SHORT TERM/AVIATION...57/DG

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA...CORRECTED
NATIONAL WEATHER SERVICE MIAMI FL
432 AM EDT THU JUN 21 2007

FLZ063-066>075-168-172>174-212200-
GLADES-HENDRY-INLAND PALM BEACH-METRO PALM BEACH-COASTAL COLLIER-
INLAND COLLIER-INLAND BROWARD-METRO BROWARD-INLAND MIAMI DADE-
METRO MIAMI DADE-MAINLAND MONROE-COASTAL PALM BEACH-
COASTAL BROWARD-COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-
432 AM EDT THU JUN 21 2007

...A FEW STRONG STORMS POSSIBLE THIS AFTERNOON...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS: A FEW THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA
THIS MORNING, ESPECIALLY OVER THE GULF WATERS TO THE LAKE OKEECHOBEE
REGION. ISOLATED TO SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP
THIS AFTERNOON, WITH THE STORMS BEING MOST CONCENTRATED ACROSS THE
LAKE REGION TO PALM BEACH COUNTY. DANGEROUS LIGHTNING STRIKES AND
HEAVY DOWNPOURS WILL ACCOMPANY THE STORMS.

WIND: A FEW STORMS ACROSS THE LAKE OKEECHOBEE REGION TO PALM BEACH
COUNTY COULD CONTAIN WIND GUSTS UP TO 50 MPH THIS AFTERNOON.

HAIL: A FEW STORMS ACROSS THE LAKE OKEECHOBEE REGION TO PALM BEACH
COUNTY COULD CONTAIN PEA SIZE HAIL THIS AFTERNOON.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SCATTERED THUNDERSTORMS ARE EXPECTED EACH DAY. DANGEROUS LIGHTNING,
HEAVY DOWNPOURS AND GUSTY WINDS ARE EXPECTED TO BE THE MAIN IMPACTS
FROM THE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

FOR MORE INFORMATION...VISIT THE NATIONAL WEATHER SERVICE IN
MIAMI WEBSITE AT WWW.WEATHER.GOV/MIAMI.

DG